The present invention relates to a connector for display inspection of a liquid crystal display panel or, more particularly, to a connector suitable for display inspection of a liquid crystal display panel having a driver IC (integrated circuit) chip directly mounted on a glass substrate for the liquid crystal display panel by the so-called COG (chip-on-glass) mounting as well as a method for the preparation thereof.
While it is the prior art technology that driver ICs of a liquid crystal display panel are mounted on the glass substrate by the so-called TAB (tape-automated bonding) mounting as an industrial mounting method, it is a trend in recent years that the method of COG mounting is widely applied to liquid crystal display panels in order to comply with the increasing requirements in various kinds of extremely compact information-processing instruments for still more compactness with a decrease in the thickness and weight, higher precision and resolution and decreased production costs in view of the advantages of the COG mounting method that the production cost can be decreased due to saving of the materials and simplification of the assembling process and a possibility is obtained for a design of a finer pitch.
The display inspection of a liquid crystal display panel, referred to as a display panel hereinafter, by the COG mounting is conducted conventionally in the following manner. Thus, as is illustrated in FIG. 1 by a vertical cross sectional view, the glass substrate 31 is first inspected for the electric circuit, then a driver IC chip 32 is mounted on the glass substrate 31 with intervention of an anisotropically electroconductive film 33 therebetween by the COG mounting method, the electrode terminals 34, 34' of the driver IC chip 32 are connected to the delivery electrodes 35 for display input signals and the delivery electrodes 36 for display output signals, respectively, and the delivery electrodes 35 for display input signals are connected to the electrodes 38 of the FPC (flexible printed circuit) board 37 with intervention of an anisotropically electroconductive film 33' to establish a mounting condition simulating an actual product to which signals are supplied to effect the final display inspection of the display panel 39.
Since it is a usual way of mounting that driver IC chips are mounted in a condition before inspection by a burn-in test, discrimination is sometimes difficult for exact location of the origin of the disorder or failure of a display panel detected by the above mentioned display inspection which may be either in the driver IC chip or in the display panel. This way of display inspection necessarily leads to a very low productivity of the assembling work which is conducted by replacing the parts of suspected failure such as the driver IC chip and FPC with respective spare parts resulting in disadvantages of a decreased yield of acceptable products and an increased cost for production.